1. Field of the Invention
This invention relates to oxidation catalyst systems. More specifically, the invention is an oxidation catalyst system that includes a sol-gel binder that allows the system to be easily coated onto a substrate.
2. Description of the Related Art
Oxidation involves the adding of an oxygen molecule or an electron to an existing molecule or compound. This process can occur naturally or can be induced. For example, a low temperature oxidation catalyst (LTOC) is required in space-based carbon dioxide (CO2) lasers where carbon monoxide (CO) produced during the lasing cycle must be converted back to CO2. Similar “CO-to-CO2” LTOCs can be used for a wide variety of other applications such as smoke filter masks, three-way automotive catalyst converters, and cabin-air filtration systems. Other applications of LTOCs not necessarily related to oxidation of “CO-to-CO2” include formaldehyde remediation systems used in industrial smoke stacks and catalytic-based sensors.
In each of these applications, preparation of the LTOC in a usable form is problematic. Typically, the LTOC must be applied to a substrate with the LTOC/substrate then being heated to adhere/bond the LTOC to the substrate. The substrates (e.g., silica gel in many mask and sensor applications, honeycomb ceramic bricks for automotive catalytic converter applications) are first coated using standard solution-based coating techniques such as slurry casting or dip-coating. These coating methods require excess amounts of the catalyst precursors to ensure adequate substrate coverage. This leads to an increase in material cost as well as causing waste handling concerns as the excess materials must be properly stored/disposed. Further, these substrate/LTOC “systems” generally require high temperature heating (i.e., up to 550° C. for many systems) to complete the LTOC-to-substrate adhering/bonding process.